Photocoagulation means and method for depilation

ABSTRACT

Depilation is effected by use of light energy of a selected frequency band concentrated into a flexible fiber small enough to enter the region of the follicle. This effects photocoagulation tissue in a limited region determined by the placement of the fiber.

350 3611 7 Ell H United States Pal Harte et al. 5] Sept. 26, 1972 [54]PHOTOCOAGULATION MEANS AND [56] References Cited 4 METHOD FOR DEPILATIONUNITED STATES PATENTS [72] Inventors: Richard A. Harte, Redwood City;

Edwin A, Amstutz Santa Clara, l 1/1970 Meyer 128/398 bOth Of Calif.3,471,215 10/1969 snitzel' 128/398 X Assignee: g y y Inc. Houston Tex-3,327,712 6/1967 Kaufrnan et al. 128/393 I Filed! 1970 PrimaryExaminer-Lawrence W. Trapp [2!] Appl NM 92598 Attorney-Laurence R. Browni Related U.S. Application Data 57 ABSTRACT Continuation-impart 0f MarchDepilation is effected by use of light energy of a 1970,abandofledselected frequency band concentrated into a flexible fibersmall enough to enter the region of the follicle. "123/3031, 128/355,128/398 This effects photocoagulation tissue in a limited region [51 1int. "A61l' d t rmined the placement of the fiber [58] Field Of Search..l23/303.l, 398, 303.18, 355

20 Claims, 3 Drawing Figures XENO N AF C PULSE D POWER SUPPLY -'SHEET 1UF 2 XENOIN AFC POWER SUPPLY 7 K PULSED INVENTORS Richard Hay-Tc, EdwinAmSt vdiz ATTORNEY PATEMEfisms m2 SHEET 2 OF 2 INVENTOR RICHARD A HARTEED IN A. AMSTU ATTORNEY PHOTOCOAGULATION MEANS AND METHOD FOR DEPILATIONThis application is a continuation-in-part of the copending abandonedapplication Ser. No. 23,921 filed Mar. 30, 1970. I

This invention relates to depilation by photocoagulation means andmethods and in particular to the use of light energy to destroy hair.

BACKGROUND OF THE INVENTION It is desirable to introduce means andmethods for removing unwanted body hair painlessly. In the conventionalstate of the art, processes where electrolysis by either galvaniccurrent electrochemical or high frequency diathermy techniques areemployed, thermal coagulation of the tissues at the hair root takesplace. These techniques, however, are not painless and are difficult toadminister and gauge. Thus, expert operators must be available todetermine dosage and conditions for use of these methods.

Light has been used, historically in the treatment of a number ofmedical problems, but until the advent of the laser, its use as acoagulator of local tissues was not widespread.

Zeiss of Germany has manufactured a Xenon arc lamp device to coagulateretinal tissue in the case of detached retina, but this was a verylarge, cumbersome, inefficient and costly device.

The ruby laser provided to be acceptable for the purpose of weldingdetached retinas, and other uses for laser coagulation have beensuggested, including the epilation of hair by destruction of vascularpapilla which feeds the germinal hair cells at the base of the follicle.

bed. In order to have effective absorption, enormous energy must bedelivered because of the mismatch, and this degree of energy wassufficient to destroy the glass fiber probes.

Literature sources provide some indices to be used in determiningthreshold levels of coagulation of human and animal tissues using lightenergy. This data is available, primarily for the vascular and pigmentedconnective tissues of the retina. As Table 1 below indicates (1) F ALEsperance Jr. and G.R. Kelly, The Threshold of the Retina to Damage byArgon Laser Radiation" Arch. Ophthal. Vol. 81, April 1969, 588 reportedthe determination of threshold levels of photocoagulation in the rabbitand monkey retina, using argon gas lasers whose output energy wascontained in several lines between 4,579 angstroms and 5,145 angstromsin the blue-green portion of the spectrum. For comparitive purposes itshould be noted that a Xenon flash lamp used in this invention was ablack body radiator with peak energy at about 4,000 angstroms and muchof its energy below 5500 angstroms. Thus, the comparison between thesesources, in regard to biological effects, is quite reasonable.

The general levels for threshold effect, as determined by visual si n oftissue coagulation, proved to be on the order of 2 to 6 joules persquare centimeter. LEsperance reported that in an earlier study donewith Xenon light by WJ. Gerraets, W.T. Ham, R.C. Wil-- liams Jr., H.A.Mueller, J. Burkhart, D. Guerry, and J .J Vos, Laser vs light coagular;A Funduscopic and Histological Study of Chonoretinal Injury as afunction of exposure time. Fed. Proceedings Vol. 24, No. 1, Part III,Jan-Feb. 1965, the threshold level was determined to be 4 joules persquare centimeter as compared with his values of 2 to 6 joules persquare centimeter for green laser light. The pulse lengths of theGerraets'study with Xenon arc lamps were varied from microseconds to 30milliseconds. A summary of the data of both studies is given in Table 1below along with comparative data on the measured performance of a modelbuilt in accordance with the present invention?" In a report following acareful measurement program of blood and tissue absorption, the presentinventors determined that maximum efficiency for coupling to hemoglobinwith minimum absorption in surrounding tissue could be accomplished byutilizing blue-green light of from 530-560 nanometer wave length. They,therefore suggested a doubled neodymium laser with spectrum output at 530 nm.

It is accordingly an object of the present invention to providepainless, simple to administer means and method of photocoagulation oftissue useful in depi1ation, and the like.

The invention, together with other objectives, features and advantagesis described hereinafter with reference to the embodiments set forth inthe accompanying drawings.

DRAWINGS FIG. 1 is a schematic view, partially in block diagram of aXenon arc photoepilator, showing in section view the probe as insertedinto a follicle;

FIG. 2 is a view in perspective, partly diagrammatic of a linear flashlamp device as used in accordance with the invention, and

FIG. 3 is an enlarged fragmentary view in elevation and in section ofthe needle inserted into the hair follicle.

Therefore, in accordance with one embodiment (see FIG. 1),photocoagulation is accomplished by transmitting pulsed light energyfrom an arc source to terminate in the region of a hair root folliclewith just enough energy in a very short pulse to destroy the lifeprocesses in the hair. In accordance with some other r 3 aspects of theinvention, specific absorption of green light energy by hemoglobin maybe effected to photocoagulate the blood vessel structure nourishing thehair root without significant absorption in other non-pigmented tissuesat or near the hair follicle.

High energy light bursts may be obtained from gas discharge lamps 5 suchas Mercury, Xenon, Argon, etc. Flash durations may be controlled byconventional pulsed power supplies 6, initiated at any desired instantby means of a switch 7, for example. Various spectral qualities can beobtained from available gas discharge lamps by employing differentgases, pressures, optical filters, etc.

Typically, lamp 5 is a high peak power pulsed Xenon arc source producingpeak powers in excess of 30 kilowatts when an operator closes switch 7,which might be a foot pedal trigger. The lamp produces a flash ofintense visible radiation in less than a few milliseconds. Because thisduration is less than the Chronaxie" for pain fibers, there is nosensation created by the energy in the body.

The flash pulse may be obtained from a bank of storage capacitors whichdelivers up to 660 joules in less than a three millisecond period. Thesecapacitors are recharged within one second, and ready to deliver thenext pulse.

A spherical mirror or lens 8 of high optical speed (f/0.5) collimatesthe light in rays 9. The collimated light is focused by a lens system 10as shown by rays 11 to be concentrated at the end of a flexible conduit12 which, for example, is a single glass fiber 100 microns in diameter.A flexible steel sheath 14 or other surgical tubing may encompass thelight conduit 12 to confine light and protect the fiber 12. Preferably,the steel sheath 14 is covered with polyvinyl chloride.

The ends of the fiber are carefully ground and polished to permit themaximum light energy to escape. Overall the probes may be about 48 to 60inches long with transmission losses that should approximate no greaterthan about 60 percent.

At the terminal or distal tip end 15 of fiber 12, where the light energyescapes, is a stainless steel hollow needle or stainless steel tubing 17of typically 125 to 200 microns in diameter and about 2 mm. to 4 mm. inlength held in a holder 16 similar to a hypodermic syringe. Thisstructure serves to introduce the fiber near the root 18 of hair 19under the skin surface 20. The needle 17 serves the function ofpreventing escape of light energy at any other point than the terminalend 15 of fiber 12 to thereby concentrate all the energy at a knownposition in the vicinity of hair follicle 21. to thereby depilate thehair without damage to other surrounding tissue. The drawing showsvarious features out of size proportion in order to show the details andthe particular mode of depilation provided by this invention.

In order to further selectively protect the adjoining tissue about thehair root 18, the light energy from are lamp 5 may be further selectedor confined to a particular waveband such as that provided by a doubleneodymium selective output laser, by introduction of selective filter22. Thus, for example, light energy entering fiber 12 may be confined togreen light of approximately 530 millimicron wavelength. This wavelengthprovides for specific absorption of the bulk of the photo energy byhemoglobin, resulting in photocoagulation of the blood vessel structure23 in the vicinity of follicle 21 that nourishes the hair root withminimal absorption in other non-pigmented tissues at or near the hairfollicle. Ultraviolet energy at about 280 millimicrons wavelength couldalso be used for maximum absorption in the protein materials at the hairroot 18.

It has been found that the amount of photo energy to be supplied by thearc lamp source for effective use in hair depilation without sensingpain or incurring significant damage to surrounding tissue is of theorder of 20 to I00 joules per square centimeter at the proximal end ofamicron diameter fiber which would give about 5 to 30 joules per squarecentimeter at the distal end of the fiber. Several successive flashesone second apart may be administered. This energy is a function of thelight intensity and pulse duration, both of which may be varied toprovide the optimum energy output at the follicle, but the time durationis preferably less than 3 milliseconds.

In laboratory experiments with humans, in photoepilation, it has beenshown that 68 percent of the hairs release well under such conditions,with hair roots often showing a matchstick" effect of burnt orshrivelled appearance. Biopsies showed no more than slight irritation inany case after such epilation and there were no reports of pain at theflash or afterwards. The surrounding tissue was not damaged.

Accordingly, the photocoagulation means and method afforded by thisembodiment results in a simple practical improvement over prior artdepilation techniques.

Another embodiment comprises a linear flash lamp having an arc lengthgreater than 10 millimeters, preferably in the order of 40 millimeters.it provides for direct takeoff by a fiber optic cable located close tothe exterior of the lamp, the takeoff being from approximately thecenter of the arc. Energy control may be ob tained by regulating thedistance of the cable end from the arc.

This embodiment does not require an extensive optical system asdescribed in the first embodiment and thus it has been found that thistype of lamp has a relatively long lifetime and gives a higher energyoutput at a not much greater energy input.

This embodiment (see FIG. 2) comprises a linear flash lamp having twoelectrodes 111 and 112 located a substantial distance apart in anenvelope 113. The electrodes 111 and 112 should be at least 10millimeters apart; for example, one such lamp on the market has an arclength of 39 millimeters. The distance should be contrasted with theshort arcs heretofore used, where the arc length was in the nature of 1mil limeter. The envelope 113 is also preferably very slender, typicallycylindrical, and in the nature of a capillary tube. A typical diameterfor such a lamp 110 is 5 millimeters, as contrasted with the 25millimeter diameter of typical short are lamps a feature which made itimpossible to get very close to the are or to get very good control ofthe location.

A pulsed power supply 114 is connected to the linear flash lamp, anysuitable pulsing means being used. The lamp 110 may be held in place bysuitable supports 115 secured to a base 116.

In conjunction with the linear flash lamp 110, this embodiment employsan optical fiber type of cable 12th, which may comprise a single glassfiber 121 typitheir lengths approximating no more than 50 per cent.

Near the outlet end of needle 125, a handle 126 is provided for use ofthe operator. The input end 124 of the fiber optic cable l2l liesclosely adjacent the flash lamp 110.

A constant energy input of about 300 joules is a typical amount with thelinear flash lamp 310, and this contrasts with the somewhat lower 60 to200 joules, a variable amount, used in a short-arc lamp of this type.

Optics such as lenses are not required in this device, and it is notedthat the energy output is greater than 0.6 millijoules as compared withan output less than 0.1 millijoule in a short are having an input of upto 200 joules. Thus, a much greater efiiciency and energy output areobtained.

in use for photoepilation, the needle 125 is inserted individually intoeach hair follicle, as shown in FIG. 3, operating on the principle ofselective damage to hair papilla and blood supply, so that it does notaffect the surrounding cells. The device is lightweight and portable,and no realignment is required between uses. It may, for example, have a5-foot cable and the probe may be 5 or 7 mils in diameter. The harmless(to all but the hair papilla and their blood supply) high intensitylight enables longer treatment sessions, and treatment of specialproblem areas. The selective absorption prevents scarring, and there areno hot probes to cause discomfort, so that inflammation and swelling areminimized.

It should be noted that an advantage of the I photoepilation techniqueover the thermolysis technique is the distance the needle must penetrateinto the skin into the hair follicle in order to destroy it. Using thephotoepilation technique the needle need only penetrate the skin intothe follicle a small distance, approximately one-sixteenth inch, whereasthe use of the thermolysis technique requires the placement of theneedle down near the root of the follicle in order to properly treat thehair. Therefore, the light transmitting means in photoepilation needonly be inserted a small distance into the follicle to destroy the hair.Thus there is less chance of accidentally damaging the surroundingtissue along with a further reduction in pain utilizing thephotoepilation technique.

in a modified form of this embodiment, the apparance is exactly the sameexcept at the output end, where in place of a needle there is merely ablunt end. In this instance, the fiber optics cable is somewhat larger,for example, about one-eighth inch in diameter and contains severalthousand individual smalldiameter fibers. Otherwise the structure isunchanged. As a result, over 20 millijoules of energy can be trum and iscapable of coagulating retinal blood vessels.

10 What is claimed is;

1. The method of epilation, comprising in combination the steps of a.Producing a pulse of high energy light by electronilight radiation,

b. Positioning a flexible thin single fiber conduit formed fromfiberoptic material capable of transmitting said light energy from thegaseous media so that the input end of said conduit collects intenselight from said high energy light and the output end of said conduit ispositioned in a hair follicle, and

c. Transmitting said pulse of light energy in said conduit with enoughenergy passed through said conduit to said hair follicle to causephotocoagulation of body tissue in the vicinity of said region at anintensity killing the hair.

2. The method defined in claim 1, including the additional step oflimiting the frequency of the light energy to a predetermined bandwidth.

3. The method defined in claim 2, including the additional step ofproducing light of a wavelength in the green region of the lightspectrum that is specifically absorbed by hemoglobin, therebyselectively photocoagulating the blood vessel structure about the regionwith the light energy becoming significantly absorbed in othernonpigmented tissues near the region. 7

v 4. The method defined in claim 2, including the additional step oflimiting the light energy supplied to the follicle to less than 3millijoules.

' 5. The method defined in claim 1 including the step of limiting thelight pulse to less than 3 milliseconds in duration.

6. The method as defined in claim 1 including the step of successivelyflashing said light energy a plurality of times at approximately 1second intervals.

7. The method defined in claim 1, including locating the output end ofsaid conduit only partly within said hair follicle.

8. Depilation apparatus for depilationby photocoagulation in a limitedregion about a hair root comprising in combination,

a. A high energy gaseous medium light source including electrical meansfor producing therein short intense pulses of light,

b. A single fiber conduit formed from fiberoptic material positioned totransmit light energy from said source to said region with a polishedend for inserting into the follicle for releasing the transmitted lightenergy in said body tissue, and

c. Means for locating said polished output end of said conduit in thefollicle.

9. Apparatus as claimed in claim 8, wherein said locating meanscomprises a needle having a cavity therein for receiving a portion, ofsaid conduit at the terminating end. .5"

cally triggering a gaseous media to produce visible 10. Apparatus asdefined in claim 8 wherein said light energy producing means furthercomprises a spherical lens of high optical speed which eollimates saidlight in rays.

11. Apparatus as defined in claim 10, including a lens system forfocusing said collimated light to be concentrated at the end of saidflexible conduit.

12. Apparatus as defined in claim 8, further comprising means forproducing light energy from said pulse to provide light in a specificrange of the spectrum.

l3. Apparatus as defined in claim 12, wherein said light as provided inthe green range of the spectrum.

14. Apparatus as claimed in claim 12, wherein said light is providedhaving a wave length of approximately 530 nanometers.

15. Apparatus as claimed in claim 8, in which means provides lightenergy at the end of said conduit to reach said region withapproximately one-half to 3 millijoules.

l6. Apparatus as claimed in claim 8 limited to produce light flashesofless than 3 milliseconds in duratron.

17. Apparatus as claimed in claim 16 adapted to produce a series ofsuccessive flashes at approximately 1 second intervals.

18. Photoepilation, comprising producing pulses primarily of blue-greenhigh-energy light in a gaseous medium across an are longer than themillimeters,

transmitting said light through a single fiber optic filament of about 5to 7 mills thickness directly from an input end adjacent said are to aneedle end,

inserting said needle end into a hair follicle, and

transmitting into said follicle the pulses for a time sufficient tocoagulate the tissue therein responsible for hair growth.

19. Photoepilation according to claim 18 wherein the energy input isapproximately 300 joules and the output is greater than 0.6 millijoules.

20. Photoepilation according to claim 18, wherein in said inserting stepsaid needle is inserted only partly into said hair follicle.

1. The method of epilation, comprising in combination the steps of a.Producing a pulse of high energy light by electronically triggering agaseous media to produce visible light radiation, b. Positioning aflexible thin single fiber conduit formed from fiberoptic materialcapable of transmitting said light energy from the gaseous media so thatthe input end of said conduit collects intense light from said highenergy light and the output end of said conduit is positioned in a hairfollicle, and c. Transmitting said pulse of light energy in said conduitwith enough energy passed through said conduit to said hair follicle tocause photocoagulation of body tissue in the vicinity of said region atan intensity killing the hair.
 2. The method defined in claim 1,including the additional step of limiting the frequency of the lightenergy to a predetermined bandwidth.
 3. The method defined in claim 2,including the additional step of producing light of a wavelength in thegreen region of the light spectrum that is specifically absorbed byhemoglobin, thereby selectively photocoagulating the blood vesselstructure about the region with the light energy becoming significantlyabsorbed in other nonpigmented tissues near the region.
 4. The methoddefined in claim 2, including the additional step of limiting the lightenergy supplied to the follicle to less than 3 millijoules.
 5. Themethod defined in claim 1 including the step of limiting the light pulseto less than 3 milliseconds in duration.
 6. The method as defined inclaim 1 including the step of successively flashing said light energy aplurality of times at approximately 1 second intervals.
 7. The methoddefined in claim 1, including locating the output end of said conduitonly partly within said hair follicle.
 8. Depilation apparatus fordepilation by photocoagulation in a limited region about a hair rootcomPrising in combination, a. A high energy gaseous medium light sourceincluding electrical means for producing therein short intense pulses oflight, b. A single fiber conduit formed from fiberoptic materialpositioned to transmit light energy from said source to said region witha polished end for inserting into the follicle for releasing thetransmitted light energy in said body tissue, and c. Means for locatingsaid polished output end of said conduit in the follicle.
 9. Apparatusas claimed in claim 8, wherein said locating means comprises a needlehaving a cavity therein for receiving a portion of said conduit at theterminating end.
 10. Apparatus as defined in claim 8 wherein said lightenergy producing means further comprises a spherical lens of highoptical speed which collimates said light in rays.
 11. Apparatus asdefined in claim 10, including a lens system for focusing saidcollimated light to be concentrated at the end of said flexible conduit.12. Apparatus as defined in claim 8, further comprising means forproducing light energy from said pulse to provide light in a specificrange of the spectrum.
 13. Apparatus as defined in claim 12, whereinsaid light as provided in the green range of the spectrum.
 14. Apparatusas claimed in claim 12, wherein said light is provided having a wavelength of approximately 530 nanometers.
 15. Apparatus as claimed inclaim 8, in which means provides light energy at the end of said conduitto reach said region with approximately one-half to 3 millijoules. 16.Apparatus as claimed in claim 8 limited to produce light flashes of lessthan 3 milliseconds in duration.
 17. Apparatus as claimed in claim 16adapted to produce a series of successive flashes at approximately 1second intervals.
 18. Photoepilation, comprising producing pulsesprimarily of blue-green high-energy light in a gaseous medium across anarc longer than the millimeters, transmitting said light through asingle fiber optic filament of about 5 to 7 mills thickness directlyfrom an input end adjacent said arc to a needle end, inserting saidneedle end into a hair follicle, and transmitting into said follicle thepulses for a time sufficient to coagulate the tissue therein responsiblefor hair growth.
 19. Photoepilation according to claim 18 wherein theenergy input is approximately 300 joules and the output is greater than0.6 millijoules.
 20. Photoepilation according to claim 18, wherein insaid inserting step said needle is inserted only partly into said hairfollicle.